Hi. Have this powersup
i get apr. 300v dc at the 2 transistors D13009K but i dont get any outputs.
Can it just be that these are fried ??

 

Probably not those but something further down the line maybe?
Chinese origin is a clue, they are renown for not being very rugged and early failure.
Max.

 

It's possible but I wouldn't bet on it. They tend to fail more spectacularly.

My bet would be bad capacitors. If you're out of things to try, replace all the electrolytic capacitors. It'll only cost a few bucks.

 

@FroceMaster

The following two issues may be from a poor photo but check them to be sure.

- Check the big cap near the transistors. It looks like that one had some gas/vapor escape at one time. If so, it is bad.

- Also, look at the large yellow-taped transformer. It looks like the yellow tape got all puckered from overheating.

- Also look at the heat sink of Q1. It looks bent and out of place and may be touching Pin 1, which it shouldn't be touching.

 

whats the 16 pin chip number, maybe a TL494 ...

 

No power to that chip. Cant remember the number right now. But it's some PWM chip

 

can you take pictures of the chip and track side of the pcb, maybe there is a fusible resistor, looks like an Atx psu.

 

I had to let out a chuckle when I read the manufacturer of those caps... "Rubicong" an obvious rip-off of the respected Japanese manufacturer "Rubycon". This is the first time I have ever heard of this outfit... I actually have a few "Rulycon" capacitors in my collection. Sadly I opened one up only to find it was an actual capacitor, not a smaller capacitor shoved into the can of a larger cap and mislabeled.

Anyways, every single one of those caps should be considered suspect and replaced on sight, at least that is how I would deal with. And check out the issue with the primary switching transistors as well, that first pin does look awfully misaligned. I think the transformer is probably ok, looks like sticky foam residue.

 

Apologies in advance for asking something so simple, but is there high voltage DC present on the rectified line supply? It couldn't just be a blown fuse could it?

 

op says there is 300V DC on the caps, pwm chip has no dc maybe a fusible resistor...